"We talked about this. What would happen if one of us was lost, in the sense of death," Waller says. "My wife told me 'If something happens to me, I want you to live on. I want you to be happy. I want you to love again.'"

He never imagined that time would come just three years into their marriage. She disappeared while snorkeling off the island of Curacao last Thursday.

"To set the facts straight, she was snorkeling with a group of friends," Allan Waller tells Eyewitness News. "And at some point, the three became separated. And when I surfaced from the dive I was doing with my best friend, they already had begun a search for her."

He says the Coast Guard quickly joined the search, and more than 50 volunteer divers looked for her well into the weekend. But no Amanda.

He planned to stay in Curacao until they found her, but he says a conversation with his father-in-law prompted him to come back to Houston.

"Her father came to me and talked to me and expressed his love. He expressed the fact that I did everything I could have done, and everything that he would have expected me to do," Waller tells us. "He told me I went above and beyond, and it was time to come home."

He made it back to Houston Wednesday and met with her family and close friends.

"I felt like there was a lot of people who clung to hope that she was out there still alive. And I wanted to give them closure so they could start to grieve, so they could start the healing."

Fighting back tears, he says he's taking this loss one day at a time. But questions remain: "I don't want to speculate on what I believe happened. I just have faith that she's in God's hands now."

The active search is now over, and Waller tells us the Coast Guard is still conducting a passive search.

He says there will be a memorial for Amanda at some point in the future.